1. Field of the Invention
The present invention generally relates to heat dissipation devices, and more particularly to a heat dissipation device having heat pipes for cooling an electronic component, such as an integrated circuit package.
2. Description of Related Art
Electronic components, such as central processing units (CPUs) comprise numerous circuits operating at high speed and generating a mass of heat that can be deleterious to their operation. Under most circumstances, it is necessary to cool the CPUs in order to maintain safe operating conditions and assure that the CPUs function properly and reliably. In the past, various approaches have been used to cool electronic components. Typically, a finned metal heat sink can be attached to an outer surface of the CPU to remove heat therefrom. The heat absorbed by the heat sink is then dissipated to ambient air. The related finned metal heat sink is made of highly heat-conductive metal, such as copper or aluminum, and generally comprises a solid metal base for contacting with the CPU to absorb the heat therefrom and a plurality of fins formed on the base for dissipating the heat. However, as the operating speed of electronic components has increased markedly in recent years, heat sinks that dissipate the heat only by metal conduction are insufficient and as a result, heat accumulated in a bottom of the metal heat sink cannot be transferred symmetrically to the whole heat dissipation device quickly enough.
Heat pipes, which operate by phase change of working liquid sealed in a hollow pipe, have been widely used due to their excellent heat transfer properties. Typically, a heat dissipation device equipped with heat pipes has a base plate, a plurality of fins arranged vertically on the base plate and a plurality of heat pipes sandwiched between the fins and the base plate. The base plate defines a plurality of grooves complementary with shape of the heat pipes. The heat pipes used in this way help to transfer heat in the base plate to the fins symmetrically. However, the heat pipes are much better than the base plate in heat transfer capability. In addition, the existence of the base plate contributes markedly to increase cost and weight of the whole heat dissipation device.
Another technique for dissipating heat includes a base including an envelope filled with working liquid (i.e. vapor chamber). This kind of heat dissipation device includes a heat sink in contact with the base. The working fluid circulates between a liquid phase and a gaseous phase in the vapor chamber in a manner such that heat is taken up at a point that is in contact with the CPU, and the heat is released at a point in contact with the heat sink. This structure has the advantage of better heat dissipation, but is complex and expensive.
Accordingly, what is needed is a heat dissipation device with heat pipes which has an enhanced heat dissipation performance and is inexpensive.